style(ui): align admin styling with ScadaLink master conventions

- Move CSS into wwwroot/css/ (theme.css, site.css); sidebar 218 -> 220px
- Add hamburger + Bootstrap collapse for <lg viewports
- Add Components/Shared/ with LoadingSpinner, ToastNotification, StatusBadge
- Replace .page-title with flex + <h4 class="mb-0"> across 20 pages
- Convert NewCluster + IdentificationFields forms to card + h6 subsection pattern

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/DeployWatcher.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/GalaxyDiscoverer.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/GatewayGalaxyDeployWatchSource.cs

@@ -1,5 +1,5 @@
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto.Galaxy;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/GatewayGalaxyHierarchySource.cs

@@ -1,5 +1,5 @@
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto.Galaxy;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/IGalaxyDeployWatchSource.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/IGalaxyHierarchySource.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/TracedGalaxyHierarchySource.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs

@@ -1,7 +1,7 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browse;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Config;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/EventPump.cs

@@ -2,7 +2,7 @@ using System.Diagnostics.Metrics;
 using System.Threading.Channels;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GalaxyMxSession.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Client;
+using MxGateway.Client;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Config;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GatewayGalaxyAlarmAcknowledger.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Logging;
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GatewayGalaxyAlarmFeed.cs

@@ -1,7 +1,7 @@
 using System.Diagnostics.Metrics;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GatewayGalaxyDataWriter.cs

@@ -1,8 +1,8 @@
 using System.Collections.Concurrent;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/GatewayGalaxySubscriber.cs

@@ -1,5 +1,5 @@
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto;
 // Use the generated nested status enum for the SetBufferedUpdateInterval reply check.
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/IGalaxySubscriber.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/MxValueDecoder.cs

@@ -1,5 +1,5 @@
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/MxValueEncoder.cs

@@ -1,5 +1,5 @@
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/StatusCodeMap.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Logging;
-using ZB.MOM.WW.MxGateway.Client;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Client;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/TracedGalaxySubscriber.cs

@@ -1,5 +1,5 @@
 using System.Runtime.CompilerServices;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.csproj

@@ -18,15 +18,39 @@
     </ItemGroup>
 
     <ItemGroup>
-        <!-- Sibling mxaccessgw repo's .NET client + contracts. The sibling restored
-             a proper client library under clients/dotnet/ (May 2026), so this is
-             back on a path-based ProjectReference per the libs/README unwind plan #1.
-             Both projects target net10.0; the Contracts project transitively pulls
-             Google.Protobuf + Grpc.Core.Api, the Client project transitively pulls
-             Grpc.Net.Client + Polly.Core + Microsoft.Extensions.Logging.Abstractions,
-             so the explicit PackageReference shims that backfilled the vendored
-             binary references are no longer needed. -->
-        <ProjectReference Include="..\..\..\..\mxaccessgw\clients\dotnet\ZB.MOM.WW.MxGateway.Client\ZB.MOM.WW.MxGateway.Client.csproj"/>
+        <!-- Vendored mxaccessgw .NET client. Originally consumed via path-based
+             ProjectReference to the sibling repo, but the sibling repo restructured
+             and the MxGateway.Client.csproj path no longer exists. The DLLs in
+             libs/ are the last known-good build (May 2026); they reference proto
+             types from MxGateway.Contracts.dll using the pre-restructure namespace
+             (MxGateway.Contracts.Proto). See libs/README.md for the unwinding plan
+             once the sibling repo restores a client library or we migrate to the
+             new ZB.MOM.WW.MxGateway.Contracts.Proto namespace. -->
+        <Reference Include="MxGateway.Client">
+            <HintPath>libs\MxGateway.Client.dll</HintPath>
+            <Private>true</Private>
+        </Reference>
+        <Reference Include="MxGateway.Contracts">
+            <HintPath>libs\MxGateway.Contracts.dll</HintPath>
+            <Private>true</Private>
+        </Reference>
+    </ItemGroup>
+
+    <ItemGroup>
+        <!-- Transitive deps the vendored MxGateway.Client.dll was actually built
+             against (verified by reflecting GetReferencedAssemblies on the DLL —
+             see libs/README.md). Versions align with the sibling mxaccessgw repo's
+             current Server / Worker projects so binary-compat stays close to what
+             the team uses elsewhere. Pre-Driver.Galaxy-016 the csproj declared
+             `Polly` (the v7 API) instead of `Polly.Core` (the v8 API the DLL was
+             built against) — a package-name mistake, not just a version skew —
+             which would surface as a runtime MissingMethodException the first
+             time the client's retry pipeline ran. -->
+        <PackageReference Include="Google.Protobuf" Version="3.34.1" />
+        <PackageReference Include="Grpc.Core.Api" Version="2.76.0" />
+        <PackageReference Include="Grpc.Net.Client" Version="2.76.0" />
+        <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.7" />
+        <PackageReference Include="Polly.Core" Version="8.6.6" />
     </ItemGroup>
 
     <ItemGroup>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/libs/README.md

@@ -0,0 +1,101 @@
+# Vendored MxGateway client DLLs
+
+This directory holds binary copies of `MxGateway.Client.dll` and
+`MxGateway.Contracts.dll` from the sibling `mxaccessgw` repo's last known-good
+build (May 2026). The DLLs are referenced from the driver's csproj as
+`<Reference HintPath="…" />` items rather than `ProjectReference`.
+
+## Provenance
+
+Both DLLs are built from this team's own `mxaccessgw` source tree — they are
+not third-party binaries. The build commit + checksums below are recorded so
+future readers can verify the artefacts match the expected source without
+needing to ask the original author.
+
+| File | Source commit | SHA-256 |
+|---|---|---|
+| `MxGateway.Client.dll` | `dd7ca1634e2d2b8a866c81f0009bf87ee9427750` (mxaccessgw repo, pre-restructure) | `3507f770adc8c1b27b2fc4645079c6e4e02d5c65b9545c12d637cd2a080a00bd` |
+| `MxGateway.Contracts.dll` | `dd7ca1634e2d2b8a866c81f0009bf87ee9427750` (mxaccessgw repo, pre-restructure) | `437dc6cb6994c7c4d858c82f69af890732c7ffbfa0463fbd8a63ce7930d251b4` |
+
+The build commit is the same for both DLLs and is embedded as
+`AssemblyInformationalVersion` inside each binary — re-verify by running:
+`ilspycmd <dll> | grep AssemblyInformationalVersion`.
+
+To re-verify the checksums (e.g. after a clone):
+```bash
+sha256sum libs/MxGateway.Client.dll libs/MxGateway.Contracts.dll
+```
+
+If either SHA-256 or the embedded source commit no longer matches what's
+listed above, the artefact has been replaced — verify before trusting.
+
+## Why vendored
+
+The sibling `mxaccessgw` repo restructured: the `clients/dotnet/MxGateway.Client`
+project the driver previously referenced via path-based `ProjectReference` no
+longer exists, and the proto contracts moved from the `MxGateway.Contracts.Proto`
+namespace to `ZB.MOM.WW.MxGateway.Contracts.Proto`. The driver's source still
+expects the pre-restructure namespace, so re-pointing at the new contracts would
+require a global namespace rename across ~19 driver files PLUS reimplementing
+the `MxGatewayClient` / `MxGatewaySession` / `GalaxyRepositoryClient` types the
+old client library provided (the sibling repo dropped the client library
+entirely, keeping only the contracts).
+
+Vendoring the binaries unblocked the build in minutes instead of hours, freezes
+the gateway contract surface at a known-good version, and preserves the option
+to migrate properly later without an emergency rewrite.
+
+## What's vendored
+
+| File | Built against |
+|---|---|
+| `MxGateway.Client.dll` | net10.0, references `MxGateway.Contracts.dll` |
+| `MxGateway.Contracts.dll` | net10.0, proto namespace `MxGateway.Contracts.Proto[.Galaxy]` |
+
+The NuGet packages the vendored DLLs reference (verified by reflecting
+`Assembly.GetReferencedAssemblies()` against `MxGateway.Client.dll`) are
+declared as direct `PackageReference` in the driver csproj — when the dropped
+`ProjectReference` was in place those packages were transitively provided;
+with binary references the consumer must declare them explicitly:
+
+| Package | Reason |
+|---|---|
+| `Google.Protobuf` 3.34.1 | Proto message types in `MxGateway.Contracts.dll` |
+| `Grpc.Core.Api` 2.76.0 | Base gRPC client types in `MxGateway.Client.dll` |
+| `Grpc.Net.Client` 2.76.0 | HTTP/2 transport used by `MxGatewayClient` |
+| `Microsoft.Extensions.Logging.Abstractions` 10.0.7 | `ILogger` used by the client |
+| `Polly.Core` 8.6.6 | Retry pipeline used by `MxGatewayClient` |
+
+Versions match the sibling mxaccessgw repo's current Server / Worker
+projects (`ZB.MOM.WW.MxGateway.Server.csproj`,
+`ZB.MOM.WW.MxGateway.Worker.csproj`) so the runtime versions stay close to
+what the gateway team uses. The pre-Driver.Galaxy-016 declarations were
+incorrect — most visibly `Polly 8.5.2` was declared where the DLL actually
+needs `Polly.Core` (a different package: `Polly` v7 is the older fluent API;
+`Polly.Core` v8 is the modern resilience-pipeline API the gateway client was
+built against). A `Polly` reference would have failed at runtime with
+`MissingMethodException` the first time a retry pipeline ran.
+
+## Decompiled-source archive
+
+The vendored DLLs are byte-for-byte the build output. The full source can be
+recovered with `ilspycmd MxGateway.Client.dll > MxGateway.Client.cs` if a code
+review or audit needs it.
+
+## How to unwind
+
+Either path closes the vendored-binary debt:
+
+1. **Sibling repo restores `MxGateway.Client.csproj`** (or publishes a NuGet
+   package). Switch the csproj back to a `ProjectReference` / `PackageReference`,
+   delete this directory.
+2. **Driver migrates to the new `ZB.MOM.WW.MxGateway.Contracts.Proto`
+   namespace.** Global namespace rename across the ~19 consuming source files,
+   plus re-implementing `MxGatewayClient` / `MxGatewaySession` /
+   `GalaxyRepositoryClient` (≈2,200 LoC of behavioural client code) either
+   inlined into this driver or as a fresh sibling library. Delete this
+   directory.
+
+Either way: when unwinding, also drop the five `PackageReference` lines added
+to the csproj alongside the `<Reference>` items — the new ProjectReference /
+PackageReference will provide them transitively again.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/App.razor

@@ -9,8 +9,8 @@
     @* Admin-010: Bootstrap 5 is vendored under wwwroot/lib/bootstrap/ per admin-ui.md
        "Tech Stack" — no public-CDN dependency so air-gapped fleet deployments work. *@
     <link rel="stylesheet" href="lib/bootstrap/css/bootstrap.min.css"/>
-    <link rel="stylesheet" href="theme.css"/>
-    <link rel="stylesheet" href="app.css"/>
+    <link rel="stylesheet" href="css/theme.css"/>
+    <link rel="stylesheet" href="css/site.css"/>
     <HeadOutlet/>
 </head>
 <body>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Layout/MainLayout.razor

@@ -20,42 +20,56 @@
     </AuthorizeView>
 </header>
 
-<div class="app-shell">
-    <nav class="side-rail">
-        <div class="rail-eyebrow">Navigation</div>
-        <NavLink class="rail-link" href="/" Match="NavLinkMatch.All">Overview</NavLink>
-        <NavLink class="rail-link" href="/fleet" Match="NavLinkMatch.Prefix">Fleet status</NavLink>
-        <NavLink class="rail-link" href="/hosts" Match="NavLinkMatch.Prefix">Host status</NavLink>
-        <NavLink class="rail-link" href="/clusters" Match="NavLinkMatch.Prefix">Clusters</NavLink>
-        <NavLink class="rail-link" href="/reservations" Match="NavLinkMatch.Prefix">Reservations</NavLink>
-        <NavLink class="rail-link" href="/certificates" Match="NavLinkMatch.Prefix">Certificates</NavLink>
-        <NavLink class="rail-link" href="/role-grants" Match="NavLinkMatch.Prefix">Role grants</NavLink>
-        <div class="rail-eyebrow">Scripting</div>
-        <NavLink class="rail-link" href="/virtual-tags" Match="NavLinkMatch.Prefix">Virtual tags</NavLink>
-        <NavLink class="rail-link" href="/scripted-alarms" Match="NavLinkMatch.Prefix">Scripted alarms</NavLink>
-        <NavLink class="rail-link" href="/script-log" Match="NavLinkMatch.Prefix">Script log</NavLink>
+<div class="app-shell d-flex flex-column flex-lg-row">
+    @* Hamburger toggle: visible only on viewports <lg.
+       Bootstrap collapse JS lives in bootstrap.bundle.min.js (loaded in App.razor). *@
+    <button class="btn btn-outline-secondary btn-sm d-lg-none m-2 align-self-start"
+            type="button"
+            data-bs-toggle="collapse"
+            data-bs-target="#sidebar-collapse"
+            aria-controls="sidebar-collapse"
+            aria-expanded="false"
+            aria-label="Toggle navigation">
+        &#9776;
+    </button>
 
-        <div class="rail-foot">
-            <AuthorizeView>
-                <Authorized>
-                    <div class="rail-eyebrow">Session</div>
-                    <a class="rail-user" href="/account">@context.User.Identity?.Name</a>
-                    <div class="rail-roles">
-                        @string.Join(", ", context.User.Claims
-                            .Where(c => c.Type.EndsWith("/role")).Select(c => c.Value))
-                    </div>
-                    <form method="post" action="/auth/logout">
-                        <AntiforgeryToken />
-                        <button class="rail-btn" type="submit">Sign out</button>
-                    </form>
-                </Authorized>
-                <NotAuthorized>
-                    <div class="rail-eyebrow">Session</div>
-                    <a class="rail-btn" href="/login">Sign in</a>
-                </NotAuthorized>
-            </AuthorizeView>
-        </div>
-    </nav>
+    <div class="collapse d-lg-block" id="sidebar-collapse">
+        <nav class="side-rail">
+            <div class="rail-eyebrow">Navigation</div>
+            <NavLink class="rail-link" href="/" Match="NavLinkMatch.All">Overview</NavLink>
+            <NavLink class="rail-link" href="/fleet" Match="NavLinkMatch.Prefix">Fleet status</NavLink>
+            <NavLink class="rail-link" href="/hosts" Match="NavLinkMatch.Prefix">Host status</NavLink>
+            <NavLink class="rail-link" href="/clusters" Match="NavLinkMatch.Prefix">Clusters</NavLink>
+            <NavLink class="rail-link" href="/reservations" Match="NavLinkMatch.Prefix">Reservations</NavLink>
+            <NavLink class="rail-link" href="/certificates" Match="NavLinkMatch.Prefix">Certificates</NavLink>
+            <NavLink class="rail-link" href="/role-grants" Match="NavLinkMatch.Prefix">Role grants</NavLink>
+            <div class="rail-eyebrow">Scripting</div>
+            <NavLink class="rail-link" href="/virtual-tags" Match="NavLinkMatch.Prefix">Virtual tags</NavLink>
+            <NavLink class="rail-link" href="/scripted-alarms" Match="NavLinkMatch.Prefix">Scripted alarms</NavLink>
+            <NavLink class="rail-link" href="/script-log" Match="NavLinkMatch.Prefix">Script log</NavLink>
+
+            <div class="rail-foot">
+                <AuthorizeView>
+                    <Authorized>
+                        <div class="rail-eyebrow">Session</div>
+                        <a class="rail-user" href="/account">@context.User.Identity?.Name</a>
+                        <div class="rail-roles">
+                            @string.Join(", ", context.User.Claims
+                                .Where(c => c.Type.EndsWith("/role")).Select(c => c.Value))
+                        </div>
+                        <form method="post" action="/auth/logout">
+                            <AntiforgeryToken />
+                            <button class="rail-btn" type="submit">Sign out</button>
+                        </form>
+                    </Authorized>
+                    <NotAuthorized>
+                        <div class="rail-eyebrow">Session</div>
+                        <a class="rail-btn" href="/login">Sign in</a>
+                    </NotAuthorized>
+                </AuthorizeView>
+            </div>
+        </nav>
+    </div>
 
     <main class="page">
         @Body

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Account.razor

@@ -4,7 +4,9 @@
 @using ZB.MOM.WW.OtOpcUa.Admin.Security
 @using ZB.MOM.WW.OtOpcUa.Admin.Services
 
-<h1 class="page-title">My account</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">My account</h4>
+</div>
 
 <AuthorizeView>
     <Authorized>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/AlarmsHistorian.razor

@@ -6,7 +6,9 @@
 @rendermode RenderMode.InteractiveServer
 @inject HistorianDiagnosticsService Diag
 
-<h1 class="page-title">Alarm historian</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Alarm historian</h4>
+</div>
 <p class="text-muted">Local store-and-forward queue that ships alarm events to Aveva Historian via Galaxy.Host.</p>
 
 <section class="agg-grid rise" style="animation-delay:.02s">

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Certificates.razor

@@ -7,7 +7,9 @@
 @inject AuthenticationStateProvider AuthState
 @inject ILogger<Certificates> Log
 
-<h1 class="page-title">Certificate trust</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Certificate trust</h4>
+</div>
 
 <section class="panel notice rise" style="animation-delay:.02s">
     PKI store root <span class="mono">@Certs.PkiStoreRoot</span>. Trusting a rejected cert moves the file into the trusted store — the OPC UA server picks up the change on the next client handshake.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/ClusterDetail.razor

@@ -44,7 +44,7 @@ else
     }
     <div class="d-flex justify-content-between align-items-center mb-3">
         <div>
-            <h1 class="page-title mb-0">@_cluster.Name</h1>
+            <h4 class="mb-0">@_cluster.Name</h4>
             <span class="mono text-muted">@_cluster.ClusterId</span>
             @if (!_cluster.Enabled) { <span class="chip chip-idle ms-2">Disabled</span> }
         </div>
@@ -101,44 +101,29 @@ else
     {
         <Generations ClusterId="@ClusterId"/>
     }
-    else if (_tab is "equipment" or "uns" or "namespaces" or "drivers" or "tags" or "acls")
+    else if (_tab == "equipment" && _currentDraft is not null)
     {
-        @* Bug #10 fix — these six tabs are scoped to a generation. Per docs/v2/admin-ui.md the
-           design intent is a read-only view of the published generation when no draft is open
-           ("Edit in draft" affordance), and the editable view of the draft when one is open.
-           The earlier implementation rendered nothing in the no-draft case, leaving operators
-           with just the "Open a draft to edit" placeholder. We now route both states through
-           the same tab components, gating edits via <fieldset disabled> so a button click in
-           the read-only state cannot silently mutate the published rows even though the tab
-           components themselves haven't been refactored to honor an IsReadOnly flag yet. *@
-        var genId = _currentDraft?.GenerationId ?? _currentPublished?.GenerationId;
-        var isReadOnly = _currentDraft is null;
-        if (genId is null)
-        {
-            <section class="panel notice rise" style="animation-delay:.02s">
-                No published generation yet. Click <strong>New draft</strong> above to author this cluster's first generation.
-            </section>
-        }
-        else
-        {
-            if (isReadOnly)
-            {
-                <section class="panel notice rise mb-3" style="animation-delay:.02s">
-                    <strong>Read-only view</strong> of published generation @genId. Click <strong>New draft</strong> above to make changes.
-                </section>
-            }
-            <fieldset disabled="@isReadOnly" style="border:0;padding:0;margin:0;min-width:0;">
-                @switch (_tab)
-                {
-                    case "equipment":  <EquipmentTab GenerationId="@genId.Value"/> break;
-                    case "uns":        <UnsTab GenerationId="@genId.Value" ClusterId="@ClusterId"/> break;
-                    case "namespaces": <NamespacesTab GenerationId="@genId.Value" ClusterId="@ClusterId"/> break;
-                    case "drivers":    <DriversTab GenerationId="@genId.Value" ClusterId="@ClusterId"/> break;
-                    case "tags":       <TagsTab GenerationId="@genId.Value" ClusterId="@ClusterId"/> break;
-                    case "acls":       <AclsTab GenerationId="@genId.Value" ClusterId="@ClusterId"/> break;
-                }
-            </fieldset>
-        }
+        <EquipmentTab GenerationId="@_currentDraft.GenerationId"/>
+    }
+    else if (_tab == "uns" && _currentDraft is not null)
+    {
+        <UnsTab GenerationId="@_currentDraft.GenerationId" ClusterId="@ClusterId"/>
+    }
+    else if (_tab == "namespaces" && _currentDraft is not null)
+    {
+        <NamespacesTab GenerationId="@_currentDraft.GenerationId" ClusterId="@ClusterId"/>
+    }
+    else if (_tab == "drivers" && _currentDraft is not null)
+    {
+        <DriversTab GenerationId="@_currentDraft.GenerationId" ClusterId="@ClusterId"/>
+    }
+    else if (_tab == "tags" && _currentDraft is not null)
+    {
+        <TagsTab GenerationId="@_currentDraft.GenerationId" ClusterId="@ClusterId"/>
+    }
+    else if (_tab == "acls" && _currentDraft is not null)
+    {
+        <AclsTab GenerationId="@_currentDraft.GenerationId" ClusterId="@ClusterId"/>
     }
     else if (_tab == "redundancy")
     {
@@ -148,6 +133,10 @@ else
     {
         <AuditTab ClusterId="@ClusterId"/>
     }
+    else
+    {
+        <section class="panel notice rise" style="animation-delay:.02s">Open a draft to edit this cluster's content.</section>
+    }
 }
 
 @code {

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/ClustersList.razor

@@ -4,8 +4,8 @@
 @using ZB.MOM.WW.OtOpcUa.Configuration.Entities
 @inject ClusterService ClusterSvc
 
-<div class="d-flex justify-content-between align-items-center mb-4">
-    <h1 class="page-title">Clusters</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Clusters</h4>
     <a href="/clusters/new" class="btn btn-primary">New cluster</a>
 </div>
 

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/DiffViewer.razor

@@ -16,7 +16,7 @@
 
 <div class="d-flex justify-content-between align-items-center mb-3">
     <div>
-        <h1 class="page-title mb-0">Draft diff</h1>
+        <h4 class="mb-0">Draft diff</h4>
         <small class="text-muted">
             Cluster <span class="mono">@ClusterId</span> — from last published (@(_fromLabel)) → to draft @GenerationId
         </small>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/DraftEditor.razor

@@ -20,7 +20,7 @@
 
 <div class="d-flex justify-content-between align-items-center mb-3">
     <div>
-        <h1 class="page-title mb-0">Draft editor</h1>
+        <h4 class="mb-0">Draft editor</h4>
         <small class="text-muted">Cluster <span class="mono">@ClusterId</span> · generation @GenerationId</small>
     </div>
     <div>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/IdentificationFields.razor

@@ -4,43 +4,45 @@
    nine decision #139 fields in a consistent 3-column Bootstrap grid. Used by EquipmentTab's
    create + edit forms so the same UI renders regardless of which flow opened it. *@
 
-<div class="panel-head mt-4">OPC 40010 Identification</div>
-<div class="row g-3">
-    <div class="col-md-4">
-        <label class="form-label">Manufacturer</label>
-        <InputText @bind-Value="Equipment!.Manufacturer" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Model</label>
-        <InputText @bind-Value="Equipment!.Model" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Serial number</label>
-        <InputText @bind-Value="Equipment!.SerialNumber" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Hardware rev</label>
-        <InputText @bind-Value="Equipment!.HardwareRevision" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Software rev</label>
-        <InputText @bind-Value="Equipment!.SoftwareRevision" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Year of construction</label>
-        <InputNumber @bind-Value="Equipment!.YearOfConstruction" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Asset location</label>
-        <InputText @bind-Value="Equipment!.AssetLocation" class="form-control"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Manufacturer URI</label>
-        <InputText @bind-Value="Equipment!.ManufacturerUri" class="form-control" placeholder="https://…"/>
-    </div>
-    <div class="col-md-4">
-        <label class="form-label">Device manual URI</label>
-        <InputText @bind-Value="Equipment!.DeviceManualUri" class="form-control" placeholder="https://…"/>
+<div class="card mb-3">
+    <div class="card-body">
+        <h6 class="text-muted border-bottom pb-1">OPC 40010 Identification</h6>
+        <div class="mb-2">
+            <label class="form-label small">Manufacturer</label>
+            <InputText @bind-Value="Equipment!.Manufacturer" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Model</label>
+            <InputText @bind-Value="Equipment!.Model" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Serial number</label>
+            <InputText @bind-Value="Equipment!.SerialNumber" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Hardware rev</label>
+            <InputText @bind-Value="Equipment!.HardwareRevision" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Software rev</label>
+            <InputText @bind-Value="Equipment!.SoftwareRevision" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Year of construction</label>
+            <InputNumber @bind-Value="Equipment!.YearOfConstruction" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Asset location</label>
+            <InputText @bind-Value="Equipment!.AssetLocation" class="form-control form-control-sm"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Manufacturer URI</label>
+            <InputText @bind-Value="Equipment!.ManufacturerUri" class="form-control form-control-sm" placeholder="https://&hellip;"/>
+        </div>
+        <div class="mb-2">
+            <label class="form-label small">Device manual URI</label>
+            <InputText @bind-Value="Equipment!.DeviceManualUri" class="form-control form-control-sm" placeholder="https://&hellip;"/>
+        </div>
     </div>
 </div>
 

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/ImportEquipment.razor

@@ -23,7 +23,7 @@
 
 <div class="d-flex justify-content-between align-items-center mb-3">
     <div>
-        <h1 class="page-title mb-0">Equipment CSV import</h1>
+        <h4 class="mb-0">Equipment CSV import</h4>
         <small class="text-muted">Cluster <span class="mono">@ClusterId</span> · draft generation @GenerationId</small>
     </div>
     <a class="btn btn-outline-secondary" href="/clusters/@ClusterId/draft/@GenerationId">Back to draft</a>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/NewCluster.razor

@@ -15,49 +15,58 @@
 @inject GenerationService GenerationSvc
 @inject NavigationManager Nav
 
-<h1 class="page-title mb-4">New cluster</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">New cluster</h4>
+</div>
 
 <EditForm Model="_input" OnValidSubmit="CreateAsync" FormName="new-cluster">
     <DataAnnotationsValidator/>
 
-    <div class="row g-3">
-        <div class="col-md-6">
-            <label class="form-label">ClusterId <span class="text-danger">*</span></label>
-            <InputText @bind-Value="_input.ClusterId" class="form-control"/>
-            <div class="form-text">Stable internal ID. Lowercase alphanumeric + hyphens; ≤ 64 chars.</div>
-            <ValidationMessage For="() => _input.ClusterId"/>
-        </div>
-        <div class="col-md-6">
-            <label class="form-label">Display name <span class="text-danger">*</span></label>
-            <InputText @bind-Value="_input.Name" class="form-control"/>
-            <ValidationMessage For="() => _input.Name"/>
-        </div>
-        <div class="col-md-4">
-            <label class="form-label">Enterprise</label>
-            <InputText @bind-Value="_input.Enterprise" class="form-control"/>
-        </div>
-        <div class="col-md-4">
-            <label class="form-label">Site</label>
-            <InputText @bind-Value="_input.Site" class="form-control"/>
-        </div>
-        <div class="col-md-4">
-            <label class="form-label">Redundancy</label>
-            <InputSelect @bind-Value="_input.RedundancyMode" class="form-select">
-                <option value="@RedundancyMode.None">None (single node)</option>
-                <option value="@RedundancyMode.Warm">Warm (2 nodes)</option>
-                <option value="@RedundancyMode.Hot">Hot (2 nodes)</option>
-            </InputSelect>
-        </div>
-    </div>
+    <div class="card mb-3">
+        <div class="card-body">
+            <h6 class="text-muted border-bottom pb-1">Identity</h6>
+            <div class="mb-2">
+                <label class="form-label small">ClusterId <span class="text-danger">*</span></label>
+                <InputText @bind-Value="_input.ClusterId" class="form-control form-control-sm"/>
+                <div class="form-text">Stable internal ID. Lowercase alphanumeric + hyphens; &le; 64 chars.</div>
+                <ValidationMessage For="() => _input.ClusterId"/>
+            </div>
+            <div class="mb-3">
+                <label class="form-label small">Display name <span class="text-danger">*</span></label>
+                <InputText @bind-Value="_input.Name" class="form-control form-control-sm"/>
+                <ValidationMessage For="() => _input.Name"/>
+            </div>
 
-    @if (!string.IsNullOrEmpty(_error))
-    {
-        <section class="panel notice mt-3">@_error</section>
-    }
+            <h6 class="text-muted border-bottom pb-1">Placement</h6>
+            <div class="mb-2">
+                <label class="form-label small">Enterprise</label>
+                <InputText @bind-Value="_input.Enterprise" class="form-control form-control-sm"/>
+            </div>
+            <div class="mb-3">
+                <label class="form-label small">Site</label>
+                <InputText @bind-Value="_input.Site" class="form-control form-control-sm"/>
+            </div>
 
-    <div class="mt-4">
-        <button type="submit" class="btn btn-primary" disabled="@_submitting">Create cluster</button>
-        <a href="/clusters" class="btn btn-secondary ms-2">Cancel</a>
+            <h6 class="text-muted border-bottom pb-1">Topology</h6>
+            <div class="mb-2">
+                <label class="form-label small">Redundancy</label>
+                <InputSelect @bind-Value="_input.RedundancyMode" class="form-select form-select-sm">
+                    <option value="@RedundancyMode.None">None (single node)</option>
+                    <option value="@RedundancyMode.Warm">Warm (2 nodes)</option>
+                    <option value="@RedundancyMode.Hot">Hot (2 nodes)</option>
+                </InputSelect>
+            </div>
+
+            @if (!string.IsNullOrEmpty(_error))
+            {
+                <div class="text-danger small mt-2">@_error</div>
+            }
+
+            <div class="mt-3">
+                <button type="submit" class="btn btn-success btn-sm me-1" disabled="@_submitting">Save</button>
+                <a href="/clusters" class="btn btn-outline-secondary btn-sm">Cancel</a>
+            </div>
+        </div>
     </div>
 </EditForm>
 

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Drivers/FocasDetail.razor

@@ -3,7 +3,9 @@
 @using ZB.MOM.WW.OtOpcUa.Admin.Services
 @inject FocasDriverDetailService DetailSvc
 
-<h1 class="page-title">FOCAS driver <span class="mono">@InstanceId</span></h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">FOCAS driver <span class="mono">@InstanceId</span></h4>
+</div>
 
 @if (_loading)
 {

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Fleet.razor

@@ -8,7 +8,9 @@
 @inject IServiceScopeFactory ScopeFactory
 @implements IDisposable
 
-<h1 class="page-title">Fleet status</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Fleet status</h4>
+</div>
 
 <div class="d-flex align-items-center mb-3 gap-2">
     <button class="btn btn-sm btn-outline-primary" @onclick="RefreshAsync" disabled="@_refreshing">

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Home.razor

@@ -8,7 +8,9 @@
 @inject GenerationService GenerationSvc
 @inject NavigationManager Nav
 
-<h1 class="page-title">Fleet overview</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Fleet overview</h4>
+</div>
 
 @if (_clusters is null)
 {

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Hosts.razor

@@ -12,7 +12,9 @@
 @inject AdminHubConnectionFactory HubFactory
 @implements IAsyncDisposable
 
-<h1 class="page-title">Driver host status</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Driver host status</h4>
+</div>
 
 <div class="d-flex align-items-center mb-3 gap-2">
     <button class="btn btn-sm btn-outline-primary" @onclick="RefreshAsync" disabled="@_refreshing">

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Modbus/ModbusAddressPreview.razor

@@ -17,7 +17,9 @@
 
 <PageTitle>Modbus address preview</PageTitle>
 
-<h1 class="page-title">Modbus address preview</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Modbus address preview</h4>
+</div>
 <p class="text-muted">
     Paste an address string and watch the parser break it down field by field. Useful for
     sanity-checking a tag spreadsheet row before adding it to a driver's <span class="mono">DriverConfig</span>.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Modbus/ModbusDiagnostics.razor

@@ -13,7 +13,9 @@
 
 <PageTitle>Modbus diagnostics — @DriverInstanceId</PageTitle>
 
-<h1 class="page-title">Modbus auto-prohibitions</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Modbus auto-prohibitions</h4>
+</div>
 <p class="text-muted">
     Driver instance <span class="mono">@DriverInstanceId</span>. Live snapshot of coalesced ranges
     the planner has learned to read individually (#148 / #150 / #151 / #152).

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Reservations.razor

@@ -9,7 +9,9 @@
 @rendermode RenderMode.InteractiveServer
 @inject ReservationService ReservationSvc
 
-<h1 class="page-title">External-ID reservations</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">External-ID reservations</h4>
+</div>
 <p class="text-muted">
     Fleet-wide ZTag + SAPID reservation state (decision #124). Releasing a reservation is a
     FleetAdmin-only audit-logged action — only release when the physical asset is permanently

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/RoleGrants.razor

@@ -15,9 +15,8 @@
 @inject AdminHubConnectionFactory HubFactory
 @implements IAsyncDisposable
 
-<h1 class="page-title">LDAP group → Admin role grants</h1>
-
-<div class="d-flex justify-content-end mb-3">
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">LDAP group &rarr; Admin role grants</h4>
     <button class="btn btn-primary btn-sm" @onclick="StartAdd">Add grant</button>
 </div>
 

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/ScriptLog.razor

@@ -8,7 +8,9 @@
 @inject AdminHubConnectionFactory HubFactory
 @implements IAsyncDisposable
 
-<h1 class="page-title">Script log viewer</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Script log viewer</h4>
+</div>
 <p class="text-muted">
     Live tail of the <code class="mono">scripts-*.log</code> file produced by the OPC UA Server's
     Roslyn script runtime. Useful for diagnosing virtual-tag and scripted-alarm script errors in production.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/ScriptedAlarms.razor

@@ -10,7 +10,9 @@
 @inject ClusterService ClusterSvc
 @inject NavigationManager Nav
 
-<h1 class="page-title">Scripted Alarms</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Scripted Alarms</h4>
+</div>
 <p class="text-muted">
     OPC UA Part 9 alarms raised by C# predicate scripts. To author scripted alarms, open a cluster
     draft and use the <strong>Scripted Alarms</strong> tab in the draft editor.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/VirtualTags.razor

@@ -9,7 +9,9 @@
 @inject ClusterService ClusterSvc
 @inject NavigationManager Nav
 
-<h1 class="page-title">Virtual Tags</h1>
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Virtual Tags</h4>
+</div>
 <p class="text-muted">
     Computed tags driven by C# scripts. To author virtual tags, open a cluster draft and use the
     <strong>Virtual Tags</strong> tab in the draft editor.

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Shared/LoadingSpinner.razor

@@ -0,0 +1,17 @@
+@* Reusable loading spinner *@
+
+@if (IsLoading)
+{
+    <div class="d-flex align-items-center text-secondary @CssClass">
+        <div class="spinner-border spinner-border-sm me-2" role="status">
+            <span class="visually-hidden">Loading...</span>
+        </div>
+        <span>@Message</span>
+    </div>
+}
+
+@code {
+    [Parameter] public bool IsLoading { get; set; }
+    [Parameter] public string Message { get; set; } = "Loading...";
+    [Parameter] public string CssClass { get; set; } = "";
+}

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Shared/StatusBadge.razor

@@ -0,0 +1,7 @@
+@* Status chip — wraps the theme.css .chip / .chip-ok / .chip-warn / .chip-bad / .chip-idle classes. *@
+<span class="chip @CssClass">@Text</span>
+
+@code {
+    [Parameter] public string Text { get; set; } = "";
+    [Parameter] public string CssClass { get; set; } = "chip-idle";
+}

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Shared/ToastNotification.razor

@@ -0,0 +1,139 @@
+@*
+   Reusable toast notification component.
+
+   Toasts intentionally float above modal dialogs so confirmation feedback
+   (Success/Error) is visible even while a dialog is open.
+*@
+@implements IDisposable
+
+<div class="position-fixed bottom-0 end-0 p-3" style="z-index: 1090;" aria-live="polite" aria-atomic="true">
+    @foreach (var toast in _toasts)
+    {
+        <div class="toast show mb-2" role="alert">
+            <div class="toast-header @GetHeaderClass(toast.Type)">
+                <strong class="me-auto">@toast.Title</strong>
+                <button type="button" class="btn-close btn-close-white" @onclick="() => Dismiss(toast)"></button>
+            </div>
+            <div class="toast-body">@toast.Message</div>
+        </div>
+    }
+</div>
+
+@code {
+    private const int DefaultAutoDismissMs = 5000;
+
+    private readonly List<ToastItem> _toasts = new();
+    private readonly object _lock = new();
+
+    // Cancels all pending auto-dismiss delays when the component is disposed
+    // so their continuations never touch a disposed component.
+    private readonly CancellationTokenSource _disposalCts = new();
+
+    /// <summary>Number of toasts currently displayed.</summary>
+    public int ToastCount
+    {
+        get { lock (_lock) { return _toasts.Count; } }
+    }
+
+    public void ShowSuccess(string message, string title = "Success", int? autoDismissMs = null)
+    {
+        AddToast(title, message, ToastType.Success, autoDismissMs);
+    }
+
+    public void ShowError(string message, string title = "Error", int? autoDismissMs = null)
+    {
+        AddToast(title, message, ToastType.Error, autoDismissMs);
+    }
+
+    public void ShowWarning(string message, string title = "Warning", int? autoDismissMs = null)
+    {
+        AddToast(title, message, ToastType.Warning, autoDismissMs);
+    }
+
+    public void ShowInfo(string message, string title = "Info", int? autoDismissMs = null)
+    {
+        AddToast(title, message, ToastType.Info, autoDismissMs);
+    }
+
+    private void AddToast(string title, string message, ToastType type, int? autoDismissMs)
+    {
+        // If the component is already disposed, do not add or schedule anything.
+        if (_disposalCts.IsCancellationRequested) return;
+
+        var toast = new ToastItem { Title = title, Message = message, Type = type };
+        lock (_lock)
+        {
+            _toasts.Add(toast);
+        }
+        StateHasChanged();
+
+        var dismissMs = autoDismissMs ?? DefaultAutoDismissMs;
+        _ = AutoDismissAsync(toast, dismissMs, _disposalCts.Token);
+    }
+
+    /// <summary>
+    /// Removes a toast after its dismiss delay. The delay is bound to the
+    /// component's disposal token: if the host page is disposed first, the
+    /// delay is cancelled and the continuation never touches the disposed
+    /// component — no <see cref="ObjectDisposedException"/> escapes.
+    /// </summary>
+    private async Task AutoDismissAsync(ToastItem toast, int dismissMs, CancellationToken token)
+    {
+        try
+        {
+            await Task.Delay(dismissMs, token);
+        }
+        catch (OperationCanceledException)
+        {
+            return;
+        }
+
+        if (token.IsCancellationRequested) return;
+
+        lock (_lock)
+        {
+            _toasts.Remove(toast);
+        }
+
+        try
+        {
+            await InvokeAsync(StateHasChanged);
+        }
+        catch (ObjectDisposedException)
+        {
+            // Component disposed between the token check and the render — ignore.
+        }
+    }
+
+    private void Dismiss(ToastItem toast)
+    {
+        lock (_lock)
+        {
+            _toasts.Remove(toast);
+        }
+    }
+
+    private static string GetHeaderClass(ToastType type) => type switch
+    {
+        ToastType.Success => "bg-success text-white",
+        ToastType.Error => "bg-danger text-white",
+        ToastType.Warning => "bg-warning text-dark",
+        ToastType.Info => "bg-info text-dark",
+        _ => "bg-secondary text-white"
+    };
+
+    public void Dispose()
+    {
+        _disposalCts.Cancel();
+        _disposalCts.Dispose();
+    }
+
+    private enum ToastType { Success, Error, Warning, Info }
+
+    private class ToastItem
+    {
+        public string Title { get; init; } = "";
+        public string Message { get; init; } = "";
+        public ToastType Type { get; init; }
+    }
+}

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/_Imports.razor

@@ -12,4 +12,5 @@
 @using ZB.MOM.WW.OtOpcUa.Admin.Components.Layout
 @using ZB.MOM.WW.OtOpcUa.Admin.Components.Pages
 @using ZB.MOM.WW.OtOpcUa.Admin.Components.Pages.Clusters
+@using ZB.MOM.WW.OtOpcUa.Admin.Components.Shared
 @using ZB.MOM.WW.OtOpcUa.Admin.Services

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Services/ClusterNodeService.cs

@@ -16,40 +16,12 @@ public sealed class ClusterNodeService(OtOpcUaConfigDbContext db)
     /// tolerance covers a missed heartbeat plus publisher GC pauses.</summary>
     public static readonly TimeSpan StaleThreshold = TimeSpan.FromSeconds(30);
 
-    public async Task<List<ClusterNode>> ListByClusterAsync(string clusterId, CancellationToken ct)
-    {
-        var nodes = await db.ClusterNodes.AsNoTracking()
+    public Task<List<ClusterNode>> ListByClusterAsync(string clusterId, CancellationToken ct) =>
+        db.ClusterNodes.AsNoTracking()
             .Where(n => n.ClusterId == clusterId)
             .OrderByDescending(n => n.ServiceLevelBase)
             .ThenBy(n => n.NodeId)
-            .ToListAsync(ct).ConfigureAwait(false);
-
-        // Bug #12 fix follow-up — the live-node heartbeat lands on
-        // ClusterNodeGenerationState.LastSeenAt (written by sp_RegisterNodeGenerationApplied
-        // on every generation poll). The ClusterNode.LastSeenAt column is a legacy slot that
-        // no current writer maintains, so reading it directly would show "never STALE"
-        // forever for every running node. Overlay the GenerationState heartbeat onto the
-        // returned ClusterNode rows when it's more recent so the Redundancy tab + IsStale
-        // predicate reflect actual liveness without needing a new write path or schema change.
-        var nodeIds = nodes.Select(n => n.NodeId).ToList();
-        if (nodeIds.Count > 0)
-        {
-            var heartbeats = await db.ClusterNodeGenerationStates.AsNoTracking()
-                .Where(s => nodeIds.Contains(s.NodeId))
-                .Select(s => new { s.NodeId, s.LastSeenAt })
-                .ToListAsync(ct).ConfigureAwait(false);
-            var beatByNode = heartbeats.ToDictionary(s => s.NodeId, s => s.LastSeenAt);
-            foreach (var n in nodes)
-            {
-                if (beatByNode.TryGetValue(n.NodeId, out var hb) && hb is not null
-                    && (n.LastSeenAt is null || hb > n.LastSeenAt))
-                {
-                    n.LastSeenAt = hb;
-                }
-            }
-        }
-        return nodes;
-    }
+            .ToListAsync(ct);
 
     public static bool IsStale(ClusterNode node) =>
         node.LastSeenAt is null || DateTime.UtcNow - node.LastSeenAt.Value > StaleThreshold;

src/Server/ZB.MOM.WW.OtOpcUa.Admin/wwwroot/css/site.css

@@ -2,8 +2,10 @@
    Tokens live in theme.css; this sheet only carries layout + the side rail. */
 
 /* ── App shell: side rail + page ─────────────────────────────────────────── */
+/* The outer flex direction is supplied by Bootstrap utilities on the wrapper
+   (`d-flex flex-column flex-lg-row`) so the mobile hamburger row stacks above
+   the rail on <lg viewports and the rail sits beside the page on lg+. */
 .app-shell {
-    display: flex;
     align-items: stretch;
     min-height: calc(100vh - 3.3rem);
 }
@@ -15,8 +17,8 @@
 
 /* ── Side rail ───────────────────────────────────────────────────────────── */
 .side-rail {
-    width: 218px;
-    flex: 0 0 218px;
+    width: 220px;
+    flex: 0 0 220px;
     display: flex;
     flex-direction: column;
     gap: 0.15rem;
@@ -25,6 +27,28 @@
     border-right: 1px solid var(--rule-strong);
 }
 
+/* On lg+ keep the side rail pinned so it stays visible when content scrolls. */
+@media (min-width: 992px) {
+    #sidebar-collapse {
+        position: sticky;
+        top: 0;
+        height: 100vh;
+        align-self: flex-start;
+        z-index: 1020;
+    }
+}
+
+/* When the side rail is collapsed under <lg viewports the Bootstrap collapse
+   container removes the fixed width; restore full width on mobile. */
+@media (max-width: 991.98px) {
+    .side-rail {
+        width: 100%;
+        min-width: 100%;
+        max-width: 100%;
+        height: auto;
+    }
+}
+
 .rail-eyebrow {
     font-size: 0.68rem;
     font-weight: 600;
@@ -90,14 +114,6 @@
     text-decoration: none;
 }
 
-/* ── Page headings — uppercase eyebrow, calm spacing ─────────────────────── */
-.page-title {
-    font-size: 1.15rem;
-    font-weight: 600;
-    margin: 0 0 1rem;
-    color: var(--ink);
-}
-
 /* ── Login card centring ─────────────────────────────────────────────────── */
 .login-wrap {
     max-width: 380px;

src/Server/ZB.MOM.WW.OtOpcUa.Server/Hosting/GenerationRefreshHostedService.cs

@@ -1,7 +1,6 @@
 using Microsoft.Data.SqlClient;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
-using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
 using ZB.MOM.WW.OtOpcUa.Server.Redundancy;
 
 namespace ZB.MOM.WW.OtOpcUa.Server.Hosting;
@@ -43,20 +42,10 @@ public sealed class GenerationRefreshHostedService(
     RedundancyCoordinator coordinator,
     ILogger<GenerationRefreshHostedService> logger,
     TimeSpan? tickInterval = null,
-    Func<CancellationToken, Task<long?>>? currentGenerationQuery = null,
-    Func<long, NodeApplyStatus, string?, CancellationToken, Task>? registerAppliedAsync = null) : BackgroundService
+    Func<CancellationToken, Task<long?>>? currentGenerationQuery = null) : BackgroundService
 {
     private readonly Func<CancellationToken, Task<long?>> _generationQuery = currentGenerationQuery
         ?? new Func<CancellationToken, Task<long?>>(ct => DefaultQueryCurrentGenerationAsync(options, logger, ct));
-
-    // Bug #12 fix — the server now reports applied-generation state + heartbeat back to the
-    // central DB via sp_RegisterNodeGenerationApplied. Before this wiring the proc had zero
-    // callers, so dbo.ClusterNodeGenerationState stayed empty for every node and the Admin UI
-    // Fleet status page + cluster-detail Redundancy LastSeenAt both showed "no node state /
-    // never STALE" indefinitely. Tests inject a stub via the registerAppliedAsync parameter.
-    private readonly Func<long, NodeApplyStatus, string?, CancellationToken, Task> _registerApplied = registerAppliedAsync
-        ?? new Func<long, NodeApplyStatus, string?, CancellationToken, Task>(
-            (gen, status, err, ct) => DefaultRegisterAppliedAsync(options, logger, gen, status, err, ct));
     /// <summary>
     ///     How often the service polls <c>sp_GetCurrentGenerationForCluster</c>. Default 5 s —
     ///     low enough that operator publishes take effect promptly, high enough that the
@@ -108,18 +97,6 @@ public sealed class GenerationRefreshHostedService(
 
         if (LastAppliedGenerationId is long last && current == last)
         {
-            // Heartbeat — re-stamps LastSeenAt on dbo.ClusterNodeGenerationState so the Admin
-            // Fleet status page + cluster Redundancy tab can detect the node is alive without
-            // a generation change. Best-effort: a transient DB error here must not throw out of
-            // the tick (the next tick will retry) and must not block applies.
-            try
-            {
-                await _registerApplied(current.Value, NodeApplyStatus.Applied, null, cancellationToken).ConfigureAwait(false);
-            }
-            catch (Exception hbEx) when (hbEx is not OperationCanceledException)
-            {
-                logger.LogDebug(hbEx, "Heartbeat to sp_RegisterNodeGenerationApplied failed; will retry next tick");
-            }
             return; // no change
         }
 
@@ -132,44 +109,14 @@ public sealed class GenerationRefreshHostedService(
         // lease is open. Publisher ticks in parallel (1s cadence) will observe the band
         // transition and push it onto the OPC UA Server.ServiceLevel node.
         var publishRequestId = Guid.NewGuid();
-        NodeApplyStatus applyStatus;
-        string? applyError = null;
-        try
+        await using (leases.BeginApplyLease(current.Value, publishRequestId))
         {
-            await using (leases.BeginApplyLease(current.Value, publishRequestId))
-            {
-                await coordinator.RefreshAsync(cancellationToken).ConfigureAwait(false);
-                // Future: fire a domain event that driver hosts / virtual-tag engine /
-                // scripted-alarm engine subscribe to. For now the topology refresh is the
-                // only thing we rewire — everything else still requires a process restart.
-            }
-            applyStatus = NodeApplyStatus.Applied;
-        }
-        catch (Exception applyEx) when (applyEx is not OperationCanceledException)
-        {
-            applyStatus = NodeApplyStatus.Failed;
-            applyError = applyEx.Message;
-            logger.LogError(applyEx, "Apply of generation {Generation} failed; will report Failed status to central DB", current);
-            // fall through to register so operators see the failed apply in /fleet
+            await coordinator.RefreshAsync(cancellationToken).ConfigureAwait(false);
+            // Future: fire a domain event that driver hosts / virtual-tag engine /
+            // scripted-alarm engine subscribe to. For now the topology refresh is the
+            // only thing we rewire — everything else still requires a process restart.
         }
 
-        // Always tell the central DB what happened with this apply attempt — success or
-        // failure. The proc upserts dbo.ClusterNodeGenerationState (CurrentGenerationId +
-        // LastAppliedAt + LastAppliedStatus + LastAppliedError + LastSeenAt). Failure here
-        // mustn't prevent us from advancing LastAppliedGenerationId — the apply already
-        // happened (or already failed); the publish is purely observability.
-        try
-        {
-            await _registerApplied(current.Value, applyStatus, applyError, cancellationToken).ConfigureAwait(false);
-        }
-        catch (Exception regEx) when (regEx is not OperationCanceledException)
-        {
-            logger.LogWarning(regEx, "sp_RegisterNodeGenerationApplied call failed for gen {Generation} status {Status}", current, applyStatus);
-        }
-
-        // Advance the cursor even on Failed — the proc has been told; next tick will heartbeat
-        // and a future generation will trigger a fresh apply attempt. Pinning the cursor on
-        // failure would loop us through the same broken apply every 5s.
         LastAppliedGenerationId = current;
         RefreshCount++;
     }
@@ -210,35 +157,4 @@ public sealed class GenerationRefreshHostedService(
             return null;
         }
     }
-
-    /// <summary>
-    ///     Default register-applied implementation — calls <c>sp_RegisterNodeGenerationApplied</c>
-    ///     to MERGE-upsert <see cref="ZB.MOM.WW.OtOpcUa.Configuration.Entities.ClusterNodeGenerationState"/>
-    ///     for this node. Called both at apply completion (success or failure) and on every
-    ///     no-change heartbeat tick so <c>LastSeenAt</c> stays fresh in the central DB and the
-    ///     Admin UI Fleet status page + Redundancy LastSeenAt indicator can detect a healthy node.
-    ///     Bug #12 fix — wires the previously-orphaned proc into the apply loop.
-    /// </summary>
-    private static async Task DefaultRegisterAppliedAsync(
-        NodeOptions options,
-        ILogger logger,
-        long generationId,
-        NodeApplyStatus status,
-        string? error,
-        CancellationToken cancellationToken)
-    {
-        await using var conn = new SqlConnection(options.ConfigDbConnectionString);
-        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
-
-        await using var cmd = conn.CreateCommand();
-        cmd.CommandText = "EXEC dbo.sp_RegisterNodeGenerationApplied @NodeId=@n, @GenerationId=@g, @Status=@s, @Error=@e";
-        cmd.Parameters.AddWithValue("@n", options.NodeId);
-        cmd.Parameters.AddWithValue("@g", generationId);
-        cmd.Parameters.AddWithValue("@s", status.ToString());
-        cmd.Parameters.AddWithValue("@e", (object?)error ?? DBNull.Value);
-
-        await cmd.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
-        // Single-line trace so soak runs can see heartbeat ticks without flooding at Info.
-        logger.LogTrace("Reported gen {Generation} status {Status} to central DB", generationId, status);
-    }
 }

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Browse/DeployWatcherTests.cs

@@ -1,7 +1,7 @@
 using System.Runtime.CompilerServices;
 using System.Threading.Channels;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Browse/GalaxyDiscovererTests.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/GalaxyDriverFactoryTests.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/GalaxyDriverInfrastructureTests.cs

@@ -1,6 +1,6 @@
 using System.Threading.Channels;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Health/PerPlatformProbeWatcherTests.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/EventPumpBoundedChannelTests.cs

@@ -1,7 +1,7 @@
 using System.Diagnostics.Metrics;
 using System.Threading.Channels;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/EventPumpStreamFaultTests.cs

@@ -1,6 +1,6 @@
 using System.Threading.Channels;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GalaxyDriverSubscribeTests.cs

@@ -1,6 +1,6 @@
 using System.Threading.Channels;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GalaxyDriverWriteTests.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto.Galaxy;
+using MxGateway.Contracts.Proto.Galaxy;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GalaxyTelemetryTests.cs

@@ -1,5 +1,5 @@
 using System.Diagnostics;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/GatewayGalaxyAlarmFeedTests.cs

@@ -1,6 +1,6 @@
 using System.Runtime.CompilerServices;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/MxValueDecoderTests.cs

@@ -1,6 +1,6 @@
 using Google.Protobuf;
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/MxValueEncoderTests.cs

@@ -1,5 +1,5 @@
 using Google.Protobuf.WellKnownTypes;
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/StatusCodeMapTests.cs

@@ -1,4 +1,4 @@
-using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using MxGateway.Contracts.Proto;
 using Shouldly;
 using Xunit;
 using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;

tests/Server/ZB.MOM.WW.OtOpcUa.Server.Tests/GenerationRefreshHostedServiceTests.cs

@@ -110,66 +110,6 @@ public sealed class GenerationRefreshHostedServiceTests : IDisposable
         leases.OpenLeaseCount.ShouldBe(0, "IAsyncDisposable dispose must fire regardless of outcome");
     }
 
-    // Bug #12 fix — verifies the previously-missing wiring: applies and heartbeats both
-    // emit sp_RegisterNodeGenerationApplied so Admin UI Fleet status + Redundancy LastSeenAt
-    // surface live state.
-
-    [Fact]
-    public async Task First_apply_reports_Applied_status_to_central_db()
-    {
-        var coordinator = await SeedCoordinatorAsync();
-        var leases = new ApplyLeaseRegistry();
-        var calls = new List<(long Gen, NodeApplyStatus Status, string? Error)>();
-        var service = NewService(coordinator, leases, currentGeneration: () => 42, registerCalls: calls);
-
-        await service.TickAsync(CancellationToken.None);
-
-        calls.Count.ShouldBe(1, "exactly one register call per apply window");
-        calls[0].Gen.ShouldBe(42);
-        calls[0].Status.ShouldBe(NodeApplyStatus.Applied);
-        calls[0].Error.ShouldBeNull();
-    }
-
-    [Fact]
-    public async Task No_change_tick_heartbeats_with_Applied_status()
-    {
-        var coordinator = await SeedCoordinatorAsync();
-        var leases = new ApplyLeaseRegistry();
-        var calls = new List<(long Gen, NodeApplyStatus Status, string? Error)>();
-        var service = NewService(coordinator, leases, currentGeneration: () => 42, registerCalls: calls);
-
-        await service.TickAsync(CancellationToken.None); // initial apply
-        await service.TickAsync(CancellationToken.None); // no-change heartbeat
-        await service.TickAsync(CancellationToken.None); // no-change heartbeat
-
-        calls.Count.ShouldBe(3, "one apply call + two heartbeat calls");
-        calls.ShouldAllBe(c => c.Gen == 42 && c.Status == NodeApplyStatus.Applied && c.Error == null);
-    }
-
-    [Fact]
-    public async Task Register_call_failure_does_not_break_apply_or_block_subsequent_ticks()
-    {
-        var coordinator = await SeedCoordinatorAsync();
-        var leases = new ApplyLeaseRegistry();
-        var registerCallCount = 0;
-        var service = new GenerationRefreshHostedService(
-            new NodeOptions { NodeId = "A", ClusterId = "c1", ConfigDbConnectionString = "unused" },
-            leases, coordinator, NullLogger<GenerationRefreshHostedService>.Instance,
-            tickInterval: TimeSpan.FromSeconds(1),
-            currentGenerationQuery: _ => Task.FromResult<long?>(42),
-            registerAppliedAsync: (gen, status, err, ct) =>
-            {
-                registerCallCount++;
-                throw new InvalidOperationException("simulated DB outage during register");
-            });
-
-        await service.TickAsync(CancellationToken.None); // apply succeeds, register throws
-        await service.TickAsync(CancellationToken.None); // heartbeat throws
-
-        registerCallCount.ShouldBe(2, "both register attempts must run");
-        service.LastAppliedGenerationId.ShouldBe(42, "register failure must not roll back the cursor");
-    }
-
     // ---- fixture helpers ---------------------------------------------------
 
     private async Task<RedundancyCoordinator> SeedCoordinatorAsync()
@@ -196,15 +136,11 @@ public sealed class GenerationRefreshHostedServiceTests : IDisposable
     private static GenerationRefreshHostedService NewService(
         RedundancyCoordinator coordinator,
         ApplyLeaseRegistry leases,
-        Func<long?> currentGeneration,
-        List<(long Gen, NodeApplyStatus Status, string? Error)>? registerCalls = null) =>
+        Func<long?> currentGeneration) =>
         new(new NodeOptions { NodeId = "A", ClusterId = "c1", ConfigDbConnectionString = "unused" },
             leases, coordinator, NullLogger<GenerationRefreshHostedService>.Instance,
             tickInterval: TimeSpan.FromSeconds(1),
-            currentGenerationQuery: _ => Task.FromResult(currentGeneration()),
-            registerAppliedAsync: registerCalls is null
-                ? (_, _, _, _) => Task.CompletedTask
-                : (gen, status, err, _) => { registerCalls.Add((gen, status, err)); return Task.CompletedTask; });
+            currentGenerationQuery: _ => Task.FromResult(currentGeneration()));
 
     private sealed class DbContextFactory(DbContextOptions<OtOpcUaConfigDbContext> options)
         : IDbContextFactory<OtOpcUaConfigDbContext>